complex

xylem, vessel elements, tracheids, pits

_____ contains two types of conducting cells: tracheids and vessel elements, which are modified sclerenchyma cells. Both types of conducting cells are hollow and nonliving, but the _____ are larger, may have perforation plates in their end walls, and are arranged to form a continuous vessel for water and mineral transport. The elongated _____, with tapered ends, form a less obvious means of transport, but water can move across the end walls and side walls because there are _____, or depressions, where the secondary wall does not form.

phloem

companion

Each sieve-tube member has a ____ cell, which does not have a nucleus. The _____ cell may control and maintain the life of both cells. _____ cells are also believed to be involved in the transport function of phloem.

pericycle

single, thin, hairs

The epidermis, which forms the outer layer of the root, consists of only a _____ layer of cells. The majority of epidermal cells are _____-walled and rectangular, but in the zone of maturation, many epidermal cells have root _____.

herbaceous

primary, secondary

_____ tissues are those new tissues formed each year from primary meristems right behind the shoot apical meristem, while _____ tissues develop during the first and subsequent years of growth from lateral meristems: vascular cambium and cork cambium.